Definition: "An ergogenic aid is any substance or phenomenon that enhances performance "

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L-Ornithine gives faster sprint during endurance activity

The amino acid L-ornithine [structure below] improves stamina and reduces fatigue during periods of extended physical exercise. Japanese researchers discovered that L-ornithine supplementation helps give you more energy for short sprints during endurance activities.

Ornithine is released in the urea cycle. This is a chain of reactions by which the body rids itself of ammonia and used up proteins. Extra ornithine speeds up these reactions, enabling the body to eliminate ammonia and other nitrogen compounds more quickly from the blood. This in turn reduces fatigue caused by exertion.

The researchers got their test subjects to cycle for four hours at 80% of the heart rate at the anaerobic threshold. Half an hour after starting to cycle and half an hour before the end of the period, the researchers got their tests subjects to cycle as fast as they could for ten seconds.

L-Ornithine gives faster sprint during endurance activity

The supplement resulted in less decrease in speed during the sprint. The effect was also accompanied by a lower accumulation of ammonia in the blood.

L-Ornithine gives faster sprint during endurance activity

"It is difficult to obtain sufficient amounts of L-ornithine from ordinary meals for antifatigue", the researchers write. "In this study, we used L-ornithine synthesized by the fermentation method. We recommend L-ornithine intake as a nutritional supplement in cases of fatigue."

The research was financed by Kyowa Hakko Kogyo, a manufacturer of L-ornithine.

Nutr Res. 2008 Nov;28(11):738-43.

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